Effect of different rootstocks on growth and quality of ‘Xinya’ grape

Abstract:【Objective】The object of this study was to evaluate the effects of rootstocks on the pheno- phase, growth, fruiting characteristics, fruit quality and disease incidence in fruit cluster of‘Xinya’grapevine, so as to select the suitable rootstocks that have low disease incidence, good coloration and comprehensive quality.【Methods】The experiment was carried out in the experimental base of the Scien- tific Research and Innovation, Zhejiang Academy of Agricultural Sciences in Haining, located in the north subtropical monsoon climate zone, with an annual temperature of 15.9 °C, a rainfall of 1 187 mm, sunshine hours of 2 002.9 h, a frost free period of 233.5 d, and sandy soil. The experimental materials were 3-year-old‘Xinya’grapevine graftings that were not treated with flower and fruit thinning.‘Xinya’scions were grafted onto twenty different rootstocks with own-rooted vines as the control. The experiment was carried out in a greenhouse and grapevine was trained in an“H”pegola trellis with a planting spacing of 2.5 m×1 m in north-south direction. The experiment was designed in a randomized block arrangement, each rootstock having 3 plots each with 5 plants. The experiment took place in 2018  to 2019. The phenophase dates, percentages of budbreak, fruiting branches and yield per plant were in- vestigated. The thicknesses of the trunk, scion stems and shoot internode of different plants were ran- domly measured with a vernier caliper. Shoot internode length was randomly measured with a tapeline, and the ratio of trunk stem thickness to scion stem thickness was calculated. Each treatment had 10 rep- licates. During ripening of grapevines, more than 50 clusters were randomly selected for each plot to in- vestigate the incidences of heat-burning, berry shrinkage, berry cracking, grey mold and anthrax. Berry samples in different treatments were collected at the same time. Thirty clusters were randomly selected from different plants for measuring cluster weight, length and width. Thirty berries were randomly col- lected from different clusters and canopy positions in each plant for evaluating berry weight as well as longitudinal and transverse diameters, which were used to calculate fruit shape index. The hardness was measured with a texture analyser and soluble solids with a hand-held refractometer. The titratable acids were determined with titration. Eeach analysis was repeated for 3 times. For each treatment, 10 berries were randomly sampled and dried in an oven at 70 °C, and the fruit moisture content was calculated. Part of the samples were ground into powder in liquid nitrogen and stored in a freezer at -80 °C for analyses of anthocyanin, total phenols, soluble sugars and organic acids, which were conducted with 3 replicates.【Results】The results of principal component analysis showed that the scores of different rootstocks from high to low were‘110R’>‘101-14’>‘Rupestrisdulot’> own-rooted vines >‘Beaumont’>‘Kang- zhen No.1’>‘420A’>‘Riparia Gloire’>‘225Ru’>‘5BB’>‘Dogridge’>‘5C’>‘Huajia No.8’>‘SO4’>‘Shen 530’>‘3309C’>‘Freedom’>‘Kangzhen No.3’>‘Kangzhen No.5’>‘1103P’>‘Macadams’. The comprehensive quality of‘Xinya’grafted on‘110R’‘101-14’and‘Rupestrisdulot’was better than that of the own-rooted vines. Among them, berry hardness, cluster weight and total sugar content of‘Xinya’grafted on‘110R’were higher than those of the own-rooted vines. The incidences of sunscald or heat-burning and grey mold in vines on‘110R’were 81.48% and 37.50% lower than in the own-rooted vines, respectively, but the cracking rate was 66.67% higher and anthocyanin content lower. The cluster weight, yield per plant, total sugar content and soluble solids in‘Xinya’grafted onto‘101- 14’were higher than in those of own-rooted vines, while the content of anthocyanin had no significant difference. The incidences of heat-burning cluster, berry cracking and grey mold were 63.77%, 8.03% and 72.83% lower than that of the own-rooted vines, respectively. Incidences of berry shrinkage and an- thrax were slight. The yield per plant, total sugar content and anthocyanin content in‘Xinya’grafted on- to‘Rupestrisdulot’were higher than in the own-rooted vines. The incidences of heat-burning, cracking and grey mold were 50.98%, 26.47% and 63.24% lower than in the own-rooted vines, respectively, and shrinkage and anthrax incidences were not found.【Conclusion】‘101-14’and‘Rupestrisdulot’can be used as the rootstocks for‘Xinya’, but‘Rupestrisdulot’is more suitable, which can improve the peel coloration and reduce incidences of heat-burning, fruit cracking and grey mold.